Alexander Holroyd couldn't suppress his smiles. On the day we met for a coffee, a poll had come out in France ahead of the elections to the National Assembly, their parliament. It showed President Macron's En Marche! on course for a landslide win.

Holroyd is bidding to be the French MP for London and, with the gusts of optimism behind Macron and his movement, he is going to struggle to lose. When the London-French community went to the polls for the presidential elections last month, Macron picked up 95 per cent of their vote — the sort of number that would make a dictator envious.

Holroyd is cut from a similar cloth to his party leader. He's smart, irritatingly young at 30, a deep Europhile and highly educated, with a string of degrees from King's College London, the LSE and the French Sciences Po. Is there a Brigitte in his life, I ask, to match Macron's wife, who has stolen the heart of France. "Yes," he blushes. "She's German." She is called Sophia.

Holroyd's conversion to politics came a year ago. He had been working on "regulatory stuff ", as he puts it, for FTI Consulting, first in Brussels and then in London, when our EU referendum happened. "It was the first time I think I felt an electoral result personally, emotionally. I have been disappointed [before] but not fundamentally impacted — it really broke something."

Alexander, or Alexandre as he appears on the ballot papers, founded the British wing of the new En Marche! party, with its promise of progress and embrace of European ideals. Holroyd organised Macron's visit to London, where thousands flocked to see him. He quit his job to campaign and then decided to stand as candidate.

He will, should he land the job, feel an empathy with his constituents. There are 130,000 registered French voters in London — though the city's French population is probably more than double that, giving rise to the joke that London is France's sixthbiggest city. Some are here as students or on short-term jobs, some are the French banking elite seduced to the City, or in London's tech start-up scene, while others have just met an English partner and had kids.